Accessibility; Drives; Electric Motor; Speed Control - Danfoss iSave 40 Series Operation Manual

Operation guide | iSave 40

6.7 Accessibility

With respect to the service and replacement of
the complete iSave unit, it is recommended to
maintain sufficient space around the unit.
The space must be sufficient enough to allow
safe lifting of the equipment, with no risk of
personal injury and/or damage to the iSave.

6.8 Drives

6.8.1 Electric motor

The iSave must only be driven by an electric
motor.
Using anything other than an electric
motor can lead to an irreparable fracture
of the iSave's internal parts.

6.8.2 Speed control

The rotation speed on the electric motor can be
controlled by a VFD. The VFD must be able to
operate at constant torque over the whole
range of speed. The direction of rotation can be
seen on the identification label.
ERD
Type iSave 40 ERD
Code no. 180FXXX
Serial no. XXXXXX04-XXX
Danfoss A/S, 6430 Nordborg, Denmark
When connecting to the power supply, check
the direction of rotation. This can be made by:
1. Looking at the fan in the end of the electric
motor.
2. Removing the plug in the bell housing and
watch the rotation of coupling.
3. Before assembling the iSave on the electric
motor, check the rotation of the shaft on the
electric motor.
Special attention has to be on NON
PROTECTED – FREE ROTATING shaft on
the electric motor. Ignorance will or
could result in personal injury.
•
Running the iSave in the wrong
direction for more than a few minutes
can cause unintended wear on the
iSave.
• If the electric motor is running at a lower
speed, extra care must be taken to
ensure that the electric motor is NOT
overheated. External cooling may be
necessary.
180R9239 | AQ299555093252en-001601 | iSave 40 | 09.2022
6.8.3 Starting torque on the iSave/ramping
the electric motor.
Because of the inertia and stick-slip friction of the
iSave internal parts, the torque will exceed the
maximum allowable operation torque for the
iSave when the speed is ramped up from zero to
maximum.
It is required to use a VFD or a soft starter.
When ramping up the speed the ramping
up time should be between 3-15 seconds
from zero to maximum. The starting
torque on the iSave can be up to 150 Nm,
(110 lbf ft).
Since the nominal torque of the motor
(11 KW [15 HP] 6 pole) is 108 Nm (80 lbf ft),
the VFD must be able to deliver 140%
start torque.
The Danfoss VFD type FC301 and FC302
can be used.
6.8.4 Torque overload protection on the
iSave.
The electric motor and iSave must always be
protected against overload.
At continuously operation the maximum torque
on the iSave must be monitored.
The electric motor must be shut of if the
maximum torque of the iSave exceeds the
defined limit.
If more electric motors are powered by the same
soft starter or VFD, each electric motor must be
equipped with "torque limit equipment" to
protect the iSave against overload.
Below are examples of equipment which can
measure the load on the electric motor or limit
the torque on the iSave.
1. VFD with integrated current monitoring relays.
2. External current monitoring relays.
See also examples of "iSave overload protection"
equipment in appendix 10.6
The electric motor and iSave must always
be protected against overload.
If the torque exceeds the maximum
operation torque, it may lead to an
irreparable fracture of the iSave´s internal
parts.
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